EDO3880 - Channons Garage, High East Street, Dorchester; evaluation Trench 5

Exeter Archaeology undertook an archaeological evaluation excavation during January 2001 at Channon’s Garage, High East Street, Dorchester, in advance of redevelopment for mixed residential and retail use. Seven trenches were excavated by machine. Trench 5 measured 3.8m x 1.2m in plan and was aligned approximately E-W, near the eastern boundary of the development area. It was excavated to a general depth of 1.4m with a machine excavated sondage at the western end extending to 2.2m. This sondage encountered an undisturbed clay subsoil (thought to overlie natural chalk) at a depth of 1.65m. The upper part of the trench was disturbed by post-medieval pits, sealed by post-medieval soil. Below a depth of between 0.4 and 0.6m, all deposits were of Roman date. Groundwater entered the trench at speed at a depth of 1.7-1.8m. The area around Trench 5 (in the vicinity of Swan Bridge, including Salisbury Street) is known to have been susceptible to flooding, even in recent years. This might account for the character of the early deposits in Trench 5, particularly the silty and gravelly upper layers. Deeper clay-based deposits at the base of the trench may be associated with the line of the Roman town's defences, thought to pass close by.